Lower Boulder Ditch

Lower Boulder Ditch

Established: October 1, 1859

Priority Number: 1

Acres under ditch: 14,980 originally

Water Source: Boulder Creek

Lower Boulder Ditch was the very first ditch to file for water on Boulder Creek. They beat Marinus Smith by one month. Marinus may have dug his ditch first, but Lower Boulder was the first to file, and in Colorado, the filing date is what counts. Lower Boulder has the most senior right in eastern Colorado.

Lower Boulder has been expanded and lengthened over the years. Today it is 32 miles long, and flows out past Frederick to just north of Fort Lupton. Lower Boulder is also now part of the C-BT system, and carries C-BT water out to the South Platte. Lower Boulder Ditch Company built Baseline Reservoir, starting construction in 1911. They also fill several reservoirs in Weld County.

Lower Boulder water is very valuable, since it is #1 in priority; many cities have bought shares and transferred them out of the ditch and into their municipal treatment plants. Only about one third of the original acres remain under the ditch.